Method call

src/core/TsdbQuery.java:1130–1324

Creates the HistogramSpanGroups to form the final results of this query. @param spans The HistogramSpans found for this query (#findHistogramSpans). Can be null, in which case the array returned will be empty. @return A possibly empty array of {@link HistogramSpanGrou

(final SortedMap<byte[], HistogramSpan> spans)

     * any 'GROUP BY' formulated in this query.
     */
     public DataPoints[] call(final SortedMap<byte[], HistogramSpan> spans) throws Exception {
       if (query_stats != null) {
         query_stats.addStat(query_index, QueryStat.QUERY_SCAN_TIME, 
                 (System.nanoTime() - TsdbQuery.this.scan_start_time));
       }
       
       final long group_build = System.nanoTime();
       if (spans == null || spans.size() <= 0) {
         if (query_stats != null) {
           query_stats.addStat(query_index, QueryStat.GROUP_BY_TIME, 0);
         }
         return NO_RESULT;
       }
       final ByteSet query_tags = null;
       // TODO
//       if (agg_tag_promotion && group_bys != null && !group_bys.isEmpty()) {
//         query_tags = new ByteSet();
//         query_tags.addAll(group_bys);
//       } else {
//         query_tags = null;
//       }
       
       final ArrayList<DataPoints> result_dp_groups = new ArrayList<DataPoints>();
       // The raw aggregator skips group bys and ignores downsampling
       if (aggregator == Aggregators.NONE) {
         for (final HistogramSpan span : spans.values()) {
           final HistogramSpanGroup group = new HistogramSpanGroup(tsdb, 
                                                 getScanStartTimeSeconds(),
                                                 getScanEndTimeSeconds(),
                                                 null,
                                                 null,
                                                 downsampler,
                                                 getStartTime(), 
                                                 getEndTime(),
                                                 query_index,
                                                 RollupQuery.isValidQuery(rollup_query),
                                                 query_tags);
           group.add(span);
           
           // create histogram data points to data points adaptor for each percentile calculation
           if (null != percentiles && percentiles.size() > 0) {
             List<DataPoints> percentile_datapoints_list = generateHistogramPercentileDataPoints(group);
             if (null != percentile_datapoints_list && percentile_datapoints_list.size() > 0)
               result_dp_groups.addAll(percentile_datapoints_list);
           }
           
           
           // create bucket metric 
           if (show_histogram_buckets) {
             List<DataPoints> bucket_datapoints_list = generateHistogramBucketDataPoints(group);
             if (null != bucket_datapoints_list && bucket_datapoints_list.size() > 0) {
               result_dp_groups.addAll(bucket_datapoints_list);
             }
           }
         } // end for
         
         int i = 0;
         DataPoints[] result = new DataPoints[result_dp_groups.size()];